Social
Why
Ultimate = for the species
groom for ectoparasite
Terms
Ethology: study of natural behaviors in natural setting
Sociobiology: behaviors explained by adaptive benefits
Comparative Psychology:
Behavioral Neuroscience (brain) & Evolutionary Psychology
predatir defense
raising of offspring
resource utilization
sifaka mob a boa George to rescue Ella
population dispersal
reproductive strategy
Proximate
Social bonding
find food
Fear reduction
territoriality
Sex
Solly Zuckerman
"Social Life of Monkeys and Apes"
London zoo: bamboo
Sexual Attraction
bring animals together
Dominance Hierarchy
each monkey has a place like in military
T.C. Schneirla
"gregarious tendency" = like to be social
obligative (genetic) -- facultative (learned)
Characteristics = Group Social Structure
monogamy
polygyny = one male with female harem
solitary forager
multi-male / multi-female
age-graded
fission (apart) / fusion (together) = community
sexually segregated
males and females not interact much
old leader
common in prosimian: mouse lemur, galago, loris, aye-aye
territorial male
social = overlapping femlaes
adolescent males/females emigrate "vagabond males"
tarsier in Phillipines, orangs
marmoset, tamarin, gibbon
each family is terrotorial
less sexual dimorphism
more parental care (communcal rearing)
both male/female offspring leave or assist rearing siblings
only 1 monkey: Mentawai langur on Siberut Island near Sumatra
Titi monkey - "tail-twining"
dad carry baby
siamang - "dueting"
not 100% loyal
tarsiers in Indonesia
huge sexual dimorphism
sons emigrate to bachelor bands + moms and daughters stay
langurs: infanticide
howler monkey, patas monkey, geunons
hamadryas & gelada baboon: social unit within sleeping herd
every 4-5 yrs
kill kids of previous adult males -> females quickly reproduce
bachelor bank takeover of single-male + female harem
one-male polygyny within large herd
geleda baboon: Bruce Effect
females miscarry if there is a male takeover
Ground-living OW monkeys
variation: ringtailed lemurs, squirrel monkeys, gorillas, chimps
female choice -> sexual dimorphism
females >> males, females related
adult male dominance hierarchy
Male emigration (sometimes female)
silverback male (α, leader)
female gorillas emigrate to other group
2 groups together is dangerous
ringtailed lemur, talapoin monkey, squirrel monkey
reduces social tensions among males
dominant females
chimps, muriqui, spider monkeys
chimps: core resident males
bonobo: female and affiliated males